Abstract
BACKGROUND: Substantial variation exists in physical functioning (PF) among patients with comparable pain severity, which may be partly explained by underlying psychological processes, like cognitive appraisal of pain and coping with pain. It remains unclear to what extent such determinants contribute to changes in PF over time, especially in older populations. Therefore, we examined longitudinal associations of cognitive appraisals and coping strategies with PF, in older adults with joint pain and comorbidity. METHODS: A prospective cohort study among 407 older adults with joint pain and comorbidity provided data over 18 months, with 6 month time-intervals. We measured PF (RAND-36), five cognitive appraisals (consequences, concerns, emotional representations, self-efficacy, catastrophizing), four coping strategies (ignoring pain, positive self-statement, increasing activity levels, activity avoidance) and three time-dependent covariates; pain intensity, anxiety and depressive symptoms. Longitudinal associations were analyzed with Generalized Estimated Equations (GEE), by testing auto-regressive models, adjusted for covariates. RESULTS: More negative thoughts about consequences of pain (β = -0.54, 95% CI = -1.02; -0.06), more catastrophizing (β = -0.67, 95% CI = -1.26; -0.07) and more activity avoidance (β = -0.32, 95% CI = -0.57; -0.08) were significantly associated with subsequent deterioration in PF, whereas higher perceived self-efficacy (β = 0.22, 95% CI = 0.12; 0.31) was associated with subsequent improvement in PF. Neither concerns, emotional representations, ignoring pain, positive self-statement nor increasing activity levels were longitudinally related to PF. CONCLUSIONS: More negative thoughts about consequences of pain, more catastrophizing and more activity avoidance contributed to deteriorated PF, whereas higher perceived self-efficacy contributed to improved PF. This knowledge may contribute to future management of functional limitations in older adults with joint pain and comorbidity.